Various techniques have been developed to provide pipe assemblies which utilize a sealing cladding of a concrete body to prevent permeation of liquid through the wall of the pipe. For example, the lining of the concrete body may be composed of a synthetic resin or plastic and especially a fiber-reinforced plastic.
Such a lining is generally not self-supporting and is carried by the concrete tube and connected to the inner wall thereof by special means.
In practice it has been found that the connection is generally not permanent and the lining cannot be said to be absolutely tight, in part because most plastics do not completely exclude diffusion through the plastic.
It is also known to provide metal pipes in which a glass tube lining is embedded in the metal shell. Such constructions are not feasible where the pipe is to have a large diameter as is the case with many water lines and especially sewage lines. The inner diameters of pipe assemblies may, for example, range from 1 to 3 meters.
In tank and landfill structures (see German Patent Document DE 37 24 882), it is proposed to provide three layers of glass shell segments so that the gaps between the segments of the layers are offset from one another and the layers are bonded together by full surface adhesive bonding, thereby ensuring that the shortest permeation path is a meandering around the edges of successive layers. In this fashion it is possible to obtain very long permeation paths which can ensure a low probability of permeation of fluids through the system.
In the prior art unit mentioned, however, the glass shell segments do not form a self-supporting unit or structure and thus it has been found to be necessary to bond the three layer stack by full surface adhesive bonding to a concrete supporting structure. This is disadvantageous because changes in the concrete substructure, for example as a result of settling of the soil, can give rise to undesirable stresses in the glass layers bonded thereto and can rupture the glass and thus eliminate the permeation tightness of the assembly.